Sure! Underplanting fruit trees, often espaliered ones, with "salleting" was common in earlier times. The salad greens made a nice ground cover and salads.

Make sure it's a true dwarf, leave it enough room to grow, and don't underplant it with spiny stuff. Treat it like any short tree or tall shrub.

Consider planting some of the pretty vegetables and herbs in your borders too ... sage, rosemary, basil in summer, etc.

I have strawberries -- though not very good ones -- intermittently throughout the acre-plus of former horse pasture because before it was pasture, and even before it was plowed for whatever was planted before that, it was an apple orchard with strawberries under the trees. Clover is often underplanted in orchards to attract bees.

That said, keep in mind that the trees and underplantings will fight each other for water and nutrients. But maybe in BC water won't be a problem, and if your soil is good, maybe nutrients won't be a problem either.